title: Chronic kidney disease progression and outcome according to serum phosphorus in mild-to-moderate kidney dysfunction.
abstract: OBJECTIVE
  Several factors might alter serum phosphate homeostasis and induce hyperhosphatemia in patients with chronic kidney disease (CKD) not requiring dialysis. However, whether and to what extent hyperphosphatemia is associated with a poor prognosis in different CKD patient groups remain to be elucidated.
  
  
  METHODS
  We utilized the "Prevenzione Insufficienza Renale Progressiva" (PIRP) database, a large project sponsored by the Emilia-Romagna Health Institute. PIRP is a collaborative network of nephrologists and general practitioners located in the Emilia-Romagna region, Italy, aimed at increasing awareness of CKD complications and optimizing CKD patient care. We identified 1716 patients who underwent a GFR and serum phosphorous assessment between 2004 and 2007. We tested whether phosphate levels ≥4.3 mg/dl are associated with the risk of CKD progression or all causes of death.
  
  
  RESULTS
  Older age and male sex were associated with lower phosphate levels. Instead, higher phosphate levels were noted in patients with diabetes. Patients with phosphate levels ≥4.3 mg/dl were at an increased risk of starting dialysis or dying (hazard ratio 2.04; 95% confidence interval [1.44, 2.90]). Notably, subgroup analyses revealed that the magnitude of the risk associated with hyperphosphatemia varied depending on age, sex, diabetes, and different stages of CKD.
  
  
  CONCLUSIONS
  These analyses lend support to the hypothesis that phosphorous abnormalities might have a negative effect on the residual renal function and prognosis in different groups of CKD patients. However, the risk associated with hyperphosphatemia might vary in specific CKD patient subgroups.
authors.affiliation: Nephrology Dialysis Hypertension Unit, Policlinico S. Orsola-Malpighi, Via P. Palagi 9, 40138 Bologna, Italy.
authors.forename: Antonio
authors.initials: A
authors.lastname: Bellasi
authors.forename: Marcora
authors.initials: M
authors.lastname: Mandreoli
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Baldrati
authors.forename: Matteo
authors.initials: M
authors.lastname: Corradini
authors.forename: Pierpaolo
authors.initials: P
authors.lastname: Di Nicolò
authors.forename: Giulio
authors.initials: G
authors.lastname: Malmusi
authors.forename: Antonio
authors.initials: A
authors.lastname: Santoro
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D018450:Disease Progression; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007674:Kidney Diseases / Q000097:blood / Q000401:mortality* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D010758:Phosphorus / Q000097:blood*
chemical_list: D010758:Phosphorus